So humans left Africa, migrated to China and started doing everything thousands of years before anyone else?
Pretty much. Most of the world's major innovations came out of China up to around 1500, when for some obscure reason Chinese innovation essentially stopped, not only relative to the West which was taking off in history's most spectacular explosion of inventiveness, but even in comparison to its own past history.
In 1500 China was on average well ahead of Europe technologically and economically, though even then probably not militarily,but it essentially stopped dead in its tracks while the West powered ahead and passed them during the 18th century, with the dramatic effects for China we see in the 19th and 20th.
I have never seen a particularly obvious explanation for this drastic change in Chinese society.